问颤振火基登录与苹果不工作的ios

EN

NoSuchMethodError (NoSuchMethodError: The method '[]' was called on null.
Receiver: null
Tried calling: []("User"))

mixin AuthenticationApple {
  static String generateNonce([int length = 32]) {
    const charset =
        '0123456789ABCDEFGHIJKLMNOPQRSTUVXYZabcdefghijklmnopqrstuvwxyz-._';
    final random = Random.secure();
    return List.generate(length, (_) => charset[random.nextInt(charset.length)])
        .join();
  }

  /// Returns the sha256 hash of [input] in hex notation.
  static String sha256ofString(String input) {
    final bytes = utf8.encode(input);
    final digest = sha256.convert(bytes);
    return digest.toString();
  }

  static Future<User> signInWithApple({BuildContext context}) async {
    User user;
    // To prevent replay attacks with the credential returned from Apple, we
    // include a nonce in the credential request. When signing in with
    // Firebase, the nonce in the id token returned by Apple, is expected to
    // match the sha256 hash of `rawNonce`.
    final rawNonce = generateNonce();
    final nonce = sha256ofString(rawNonce);

    // Request credential for the currently signed in Apple account.
    final appleCredential = await SignInWithApple.getAppleIDCredential(
      scopes: [
        AppleIDAuthorizationScopes.email,
        AppleIDAuthorizationScopes.fullName,
      ],
      nonce: nonce,
    );

    // Create an `OAuthCredential` from the credential returned by Apple.
    final oauthCredential = OAuthProvider('apple.com').credential(
      idToken: appleCredential.identityToken,
      rawNonce: rawNonce,
    );
    try {
      // Sign in the user with Firebase. If the nonce we generated earlier does
      // not match the nonce in `appleCredential.identityToken`, sign in will fail.
      final UserCredential userCredential =
          await FirebaseAuth.instance.signInWithCredential(oauthCredential);
      user = userCredential.user;
    } on FirebaseAuthException catch (e) {
      if (e.code == 'account-exists-with-different-credential') {
        ScaffoldMessenger.of(context).showSnackBar(
          AppWidget.customSnackBar(
            content: 'The account already exists with a different credential.',
          ),
        );
      } else if (e.code == 'invalid-credential') {
        ScaffoldMessenger.of(context).showSnackBar(
          AppWidget.customSnackBar(
            content: 'Error occurred while accessing credentials. Try again.',
          ),
        );
      }
    } catch (e) {
      ScaffoldMessenger.of(context).showSnackBar(
        AppWidget.customSnackBar(
          content: 'Error occurred using Apple Sign-In. Try again.',
        ),
      );
    }
    return user;
  }
}